Assess burn scars with satellite imagery

In the summer of 2015, wildfires raged through Glacier National Park in Montana. Following fires such as these, it is critical for forest management services to measure the burn scars, as they will serve as a baseline to monitor forest regeneration.

In this tutorial, you'll use Landsat 8 satellite images from before and after the fires to visualize the burn scars in ArcGIS Pro. Then, you'll calculate the damage using a Normalized Burn Ratio and publish the data as a feature class to share with your forest management services colleagues.

This tutorial was last tested on March 24, 2026, using ArcGIS Pro 3.6. If you're using a different version of ArcGIS Pro, you may encounter different functionality and results.

Requirements

• ArcGIS Pro (see options for software access)
• ArcGIS Spatial Analyst extension or ArcGIS Image Analyst
• Publisher or Administrator role in an ArcGIS organization: ArcGIS Online (see options for software access) or ArcGIS Enterprise (learn more)

Compare band combinations

First, you'll take an initial look at the burn scar using Landsat 8 imagery. After acquainting yourself with the study area, you'll change the band combination of the imagery to better see the burned areas. Then, you'll create a custom combination to emphasize burn scars.

Download the project

Before you begin your analysis, you'll download and open a project package containing the data for your assignment.

1. Download the Montana Fires Project Package.

   Project packages contain all maps, data, folders, and toolboxes for a project.

   Note:

   Depending on your web browser, you may have been prompted to choose the file's location before you began the download. Most browsers download to your computer's Downloads folder by default, and you can then move the package to a location of your choice.

   Based on your settings, the downloaded project package might open on its own in ArcGIS Pro. Otherwise, you'll open it now.

2. Double-click the file to open it in ArcGIS Pro.

   Note:

   If you don't have access to ArcGIS Pro or an ArcGIS organizational account, see options for software access.

   The project opens with two layers in the Contents pane.

   

   The layers, 2014.tif and 2015.tif, are imagery layers and are turned off. The map is centered around Glacier National Park in Montana, which comprises more than 1 million acres. The Topographic layer is the basemap used for this project.

Enhance the imagery

Now that you've accessed the project data, you'll look at and enhance the imagery. The layers, 2014.tif and 2015.tif, are two Landsat 8 imagery layers, clipped to a study area around two particular wildfires: the Thompson Fire and the Reynolds Creek Fire. Both images were captured in August of different years.

1. In the Contents pane, check the box next to the 2014.tif layer to turn it on.

   

2. Right-click the layer and choose Zoom To Layer.

   

   The map zooms to the image location.

   

   The image is dark and difficult to see. You'll adjust the brightness, contrast, and gamma to better see the image. Brightness determines whether an image as a whole is displayed lighter or darker, while contrast adjusts the difference between the darkest and lightest colors.

   Gamma determines how the middle values of an image (from dark to light grays) will be distributed. The human eye does not perceive levels of brightness the same way a digital camera does. Gamma encoding redistributes tones across the image to make them better match the human eye's perception. In particular, a higher gamma value improves the ability for the human eye to differentiate between dark tones. With a lower gamma value, darker areas in an image can appear uniformly dark and the features they contain can be hard to distinguish. A higher gamma value introduces more variations in the dark tones and makes the features appearing in the dark areas easier to distinguish.

   Increasing all of three parameters will improve the visibility of the image.

3. If necessary, in the Contents pane, click the 2014.tif layer to select it.
4. On the ribbon, click the Raster Layer tab. In the Enhancement group, change the following parameters:
   • Change Layer Brightness to 20.
   • Change Layer Contrast to 25.
   • Change Layer Gamma to 1.8.

   Note:

   You may need to press Enter after changing each parameter to apply the changes.

   

   The image updates.

   

   The environment now appears in more detail. The mountainous terrain is marked by valleys and lakes. Some of the peaks are snowcapped while others are obscured by cloud cover. Since this image was taken in August, the mountains may have glaciers or permanent snow. The terrain also appears to have ample vegetation. The type of vegetation and the slope of the mountains affect fire, particularly the speed at which it spreads. This is what the area looked like in 2014, before the Reynolds Creek and Thompson fires. Next, you'll review the 2015 imagery.

5. In the Contents pane, uncheck the 2014.tif layer to turn it off. Check the 2015.tif layer to turn it on.

   The 2015.tif image becomes visible.

   

   The default appearance of the 2015 image is clearer than the 2014 image was, but it could still use some brightness, contrast, and gamma correction.

6. In the Contents pane, click the 2015.tif layer to select it.
7. On the Raster Layer tab, in the Enhancement group, change the following parameters:
   • Change Layer Brightness to 10.
   • Change Layer Contrast to 15.
   • Change Layer Gamma to 1.5.

   The image updates.

   

   The 2015 imagery has two distinct differences from the 2014 imagery. First, a large gray cloud covers the central-southern portion of the image. This cloud is actually smoke from the Thompson Fire, which was still burning when this image was taken.

   

   Secondly, to the upper left of the lake in the central-northern part of the image is a long reddish streak. This is the burn scar of the Reynolds Creek Fire, which had stopped burning by the time this image was taken.

   

   While both fires are visible, their exact boundaries are unclear. Next, you'll experiment with various band combinations of the imagery to find one that best emphasizes the burn scars.

View various band combinations

Landsat imagery measures ranges of wavelengths of the electromagnetic spectrum, including some that are invisible to the human eye. These ranges are called spectral bands. The bands are described in the following table:

Number	Name	What this band shows best
1	Coastal Aerosol	Shallow water, fine dust particles
2	Blue	Deep water, atmosphere
3	Green	Vegetation
4	Red	Human-made objects, soil, vegetation
5	Near Infrared	Shorelines, vegetation
6	Shortwave Infrared 1	Cloud penetration, soil and vegetation moisture
7	Shortwave Infrared 2	Improved cloud penetration, soil and vegetation moisture
8	Panchromatic	Black-and-white imagery, crisper detail
9	Cirrus	Cirrus clouds
10	Thermal Infrared 1	Thermal mapping, estimated soil moisture
11	Thermal Infrared 2	Improved thermal mapping, estimated soil moisture

Bands 2, 3, and 4 (Blue, Green, and Red) make up the spectrum of light visible to the human eye. The Natural Color band combination, which your imagery currently uses, combines these three bands to approximate how imagery would look to a person. Next, you'll change the band combination to emphasize the fires and better see their boundaries.

1. In the Contents pane, confirm that the 2015.tif layer is selected.

   Under the layer name are the bands the image currently uses: Blue, Green, and Red bands that encompass visible light. The Red and Green bands emphasize vegetation, which can be useful for seeing fires because of the contrast between highly vegetated areas untouched by fire and areas where vegetation has been destroyed by fire. Using another band that emphasizes vegetation, such as Near Infrared (band 5), could improve the contrast.

2. On the Raster Layer tab, in the Rendering group, click Band Combination and choose Color Infrared.

   

   The image changes to show the new band combination.

   

   In the Contents pane, the bands beneath the layer name also change, indicating that this image combines Near Infrared, Red, and Green bands (3, 4, and 5). Since the Near Infrared band is normally invisible to the human eye, it is displayed through the Red channel. As a result, the Red and Green bands are displayed through the Green and Blue channels.

   

   Note:

   The image resulting from combining three imagery bands and displaying them through the Red, Green, and Blue channels is named an RGB composite. Any band can be used in any of the three RGB composite channels, which is why it's possible to have the Red band displayed through the Green channel. In the legend, the color of the symbol and the first word indicate the composite color (or channel), while the second word indicates the band chosen.

   On the map, vegetation appears as red. Both fire areas appear as dark brown. Compared to the original image, the fires appear more clearly, especially the Reynolds Creek Fire north of the lake. However, the Thompson Fire is still somewhat obscured by smoke. Next, you'll try a band combination using the Shortwave Infrared bands (6 and 7), which penetrate clouds.

3. On the Raster Layer tab, click Band Combination and choose Land/Water Interface.

   The bands update and the imagery changes.

   

   In the Contents pane, the bands beneath the layer change to both Shortwave Infrared bands and the Near Infrared band, meaning this image combines bands 5, 6, and 7. Although the main purpose of this combination is to delineate land and water, it also penetrates haze (or, in this case, smoke). Almost no smoke appears around the Thompson Fire, making its boundaries much clearer. However, the burned areas appear orange while the surrounding mountain slopes appear yellow. This makes the Reynolds Creek Fire, which spreads into the mountains, more difficult to see.

4. Click Band Combination and choose Vegetation Analysis.

   The bands update and the imagery changes.

   

   This combination uses the Red, Near Infrared, and Shortwave Infrared 1 bands (4, 5, 6). It combines the emphasis on vegetation from the Color Infrared combination with some of the haze penetration of the Land/Water Interface combination. Although some smoke is visible around the Thompson Fire and the Reynolds Creek Fire blends somewhat into the mountain slopes, these issues are less severe than in the previous combinations.

   If the haze could be reduced just a little more, this image would probably be the best for digitizing the burn scars. However, none of the remaining default band combinations improve on the three you looked at. To customize the imagery to your needs, you'll create a custom band combination.

Create a custom band combination

So far, you've used preconfigured band combinations. Next, you'll choose your own bands to create a custom band combination that will improve on the Vegetation Analysis band combination by further reducing haze.

The Vegetation Analysis band combination uses the Shortwave Infrared 1 band to reduce haze and the Near Infrared and Red bands to emphasize vegetation. Switching Shortwave Infrared 1 to Shortwave Infrared 2 would improve the haze (or cloud) penetration.

1. In the Contents pane, right-click the ShortWaveInfrared_1 band and choose ShortWaveInfrared_2.

   

   Note:

   The Panchromatic band (band 8) and both Thermal Infrared bands (bands 10 and 11) have been removed from the data provided in this tutorial package, which is why they do not appear in the list of bands.

   The band automatically changes, as does the image on the map. The difference on the map is subtle, but there is a slight improvement in the clarity of the burn scar display. Next, you'll replace the Red band with the Blue band.

2. Right-click the Blue color and choose Blue.

   

   The image on the map changes slightly. Although still visible, the haze has been reduced.

   

   To access this band combination in the future, you'll save it as one of the default combinations on the Raster Layer tab.

3. On the Raster Layer tab, click Band Combination and choose Custom.

   

   The Custom Band Combination window appears.

4. Set the following bands:
   • For the red color, choose ShortWaveInfrared_2.
   • For the green color, choose NearInfrared.
   • For the blue color, choose Blue.

   

5. For Name, type Burn Scar Analysis. Click Save.

   The custom band combination is added to the Band Combination menu, allowing you to quickly apply it to other imagery (or reapply it to this image if you change the band combination again).

   Note:

   You can remove custom band combinations from the list only after starting a new session of ArcGIS Pro.

6. On the Quick Access Toolbar, click the Save Project button.

   

   Note:

   If a Save Project window appears explaining the project was created using a previous version of ArcGIS Pro and asking if you want to save it in the current version, click Yes.

   The project is saved.

You've displayed imagery of two fires in Glacier National Park, first as a natural color image and then using other band combinations that emphasized the burned areas better. Ultimately, you created a custom band combination specifically meant to highlight burn scars. Although this custom combination is more suitable for deriving exact burn scar boundaries, it still requires some visual interpretation to determine what is burned and what is not. Next, you'll use a mathematical formula called a burn index to calculate burned areas quantitatively, providing an even more exact measure of where the fires raged.

Calculate the burn index

Previously, you looked at the imagery through various spectral band combinations to visually identify burn scars. Next, you'll use an index that identifies burned areas quantitatively. This index is called the Normalized Burn Ratio (NBR), and it mathematically compares the Near Infrared and Shortwave Infrared 2 bands of an image (bands 5 and 7, respectively) to determine burn severity.

You'll apply the NBR to the 2014.tif and 2015.tif imagery. Then, you'll compute the difference between the two images to determine the amount of change pre- and postfire. The result will be mathematically computed burn scars.

Calculate NBR

First, you'll calculate the NBR for the 2014 image.

1. In the Contents pane, select the 2014.tif layer.
2. On the ribbon, click the Imagery tab. In the Tools group, click Indices.

   

3. In the Landscape section, click NBR.

   

4. In the NBR window, for Near Infrared Band Index, confirm that 5 - Nearinfrared is chosen. For Shortwave Infrared Band Index, choose 7 - ShortWaveInfrared_2.

   

5. Click OK.

   The NBR_2014.tif layer appears in the Contents pane and on the map.

   

   An NBR layer values can vary maximally between -1 and 1, although not all values might be present in a specific layer. Next, you'll calculate the NBR for the 2015 image.

6. In the Contents pane, select the 2015.tif layer.
7. On the ribbon, in the Tools group, click Indices and choose NBR.
8. In the NBR window, for Near Infrared Band Index, confirm that 5 - Nearinfrared is chosen. For Shortwave Infrared Band Index, choose 7 - ShortWaveInfrared_2.
9. Click OK.

   The NBR_2015.tif layer appears in the Contents pane and on the map.

Determine change in NBR

Next, you'll use the Difference tool to calculate the change in NBR between the two images. In doing so, you'll identify the areas where NBR values have sharply increased between 2014 and 2015. These areas will correspond to the burn scars.

The difference you want to compute is NBR_2014.tif - NBR_2015.tif. The Difference tool takes rasters in the order they are selected in the Contents pane.

1. In the Contents pane, click NBR_2014.tif to select it. Press Ctrl and click NBR_2015.tif to select it too.

   

   Note:

   Make sure to select NBR_2014.tif first, followed by NBR_2015.tif. Selecting NBR_2015.tif first would result in finding the difference between NBR_2015.tif - NBR_2014.tif, giving you different results.

2. On the ribbon, on the Imagery tab, in the Tools group, click the Process drop-down arrow and choose Difference.

   

   The difference raster, Difference_NBR_2014.tif_NBR_2015.tif, is added to the Contents pane and to the map.

   

   The fire locations now appear almost solid white, contrasting strongly against the gray and black areas. The only other white areas are the snowy mountainous areas, which are generally not conterminous with the fire areas. You can heighten the contrast by symbolizing the image. First, you'll change the name of the layer.

3. In the Contents pane, click Difference_NBR_2014.tif_NBR_2015.tif to make its name editable. Type change_nbr and press Enter.
4. Under change_nbr, click the color ramp.

   

   The Symbology pane appears. The layer symbology for change_nbr is determined by a color ramp instead of an RGB composite because, like the other NBR layers, it contains only one band.

5. In the Symbology pane, click Color scheme and check Show names.

   

6. In the list of color ramps, choose the Condition Number color ramp.

   

7. For Stretch type, choose Standard Deviation.

   

   The symbology updates.

   

   Both fires are now clearly demarcated on the map in bright red.

8. Close the Symbology pane.

   You no longer need the original NBR layers, so you'll remove them.

9. In the Contents pane, right-click the NBR_2015.tif layer and choose Remove.

   

10. Remove the NBR_2014.tif layer.
11. Save the project.

You now have a clear enough image of the fire extents to digitize them as polygon features to share with your colleagues from the Montana Forest Management Services.

Digitize the fire area

Next, you'll create a feature class to store the new polygons. Then, you'll use editing tools to draw the polygon features, following the approximate boundaries of both fires. Finally, you'll compute the area in acres for each burn scar.

Create a feature class

You'll start by creating a feature class, which you'll later use to contain the digitized fire area polygons.

1. On the ribbon, click the View tab. In the Windows group, choose Catalog Pane.

   

2. In the Catalog pane, expand the Databases folder.

   

   The folder contains montana_fires.gdb, the default geodatabase for the project, where you'll create the new feature class.

3. Right-click montana_fires.gdb, point to New, and choose Feature Class.

   

   The Create Feature Class pane appears.

4. For Name, type Fires.

   

5. Leave the other parameters unchanged. At the bottom of the pane, click Finish.

   The new empty Fires feature class is added to your map and Contents pane. Because the new feature class's default symbology has a solid fill, it will be challenging to accurately trace the map feature, so you'll update the symbology.

6. In the Contents pane, click the symbol for Fires.

   

   Note:

   The symbology color of the layer is randomly generated and may differ from the example image.

   The Symbology pane appears. You'll choose a symbol that has an outline but no fill.

7. In the Symbology pane, on the Gallery tab, click Black Outline (2 pts).

   

   Tip:

   Point to a symbol to see its full name.

   The layer symbol updates in the Contents pane. The layer is configured and ready for editing.

8. Close the Symbology pane.

Draw boundary polygons

Next, you'll use editing tools to trace the edges of the Reynolds and Thompson Fires, digitizing the burn scar.

1. On the map, zoom to the Reynolds Creek Fire (the northernmost fire).

   

2. On the ribbon, click the Edit tab. In the Features group, click Create.

   

   The Create Features pane appears. It contains the layers for which you can create features.

3. In the Create Features pane, click Fires. If necessary, click the Polygon button.

   

   The pointer changes to crosshairs when you move it over the map.

4. Click anywhere on the edge of the Reynolds Creek Fire area to begin drawing a polygon feature.

   

5. Click several other points along the burn scar boundary.

   Note:

   If necessary, zoom in.

   Each time you click, another vertex is placed.

   

   Tip:

   If you are unhappy with the placement of a vertex, press Ctrl+Z to remove it. To navigate the map while adding vertices, press the C key to temporarily activate normal navigation.

6. Add vertices all along the edge of the fire area.

   Note:

   The more vertices you add, the more accurate your feature will be. Since you're only doing a tutorial, don't worry about creating a perfect feature. Your feature does not need to be as detailed or accurate as the one in the example images.

7. When you've finished placing vertices, double-click the final vertex to finish creating the feature.

   

8. On the Edit tab, in the Manage Edits group, click Save.

   

9. In the Save Edits window, click Yes to save all edits.

   Tip:

   If you want to correct the position of a vertex after saving your polygon, on the Edit tab, in the Tools group, click Edit Vertices. On the map, click the vertex and drag it to a new position. When you are done, on the floating toolbar, click the Finish button. On the Edit tab, click Save.

   Alternatively, you can delete the entire feature and start over. To do so, select the polygon. On the Edit tab, in the Features group, click Delete.

   Next, you'll digitize the Thompson Fire area.

10. Press the Esc key to return to the map navigation mode.
11. Navigate to the Thompson Fire.

    

12. In the Create Features pane, under Fires, click the Polygon button.
13. Digitize the Thompson Fire.

    

14. When you're satisfied with your feature, save the edits.
15. Close the Create Features pane. In the Contents pane, right-click change_nbr and choose Zoom To Layer.

    Note:

    Digitizing features manually, as you just did, works well when you have a small number of features. When analyzing larger areas, you might want to explore more automated vectorization methods, such as the Raster to Polygon tool.

Add attribute information

You've created features for both fires, but they currently have no attribute information. You'll edit the attribute table to identify each fire and calculate each fire's acreage.

1. In the Contents pane, right-click Fires and choose Attribute Table.

   

   The attribute table has two features in the order they were digitized. The last feature you created, the Thompson Fire, might still be selected.

   

2. On the attribute table ribbon, click the Clear Selection button.

   

   The perimeter and area of the fires have already been calculated in the Shape_Length and Shape_Area attributes, but these calculations are in square meters. A more standard measurement for area would be acres. You'll create a new attribute and populate it with that information.

3. On the attribute table ribbon, click the Add Field button.

   

   The Fields view opens, with an empty field at the bottom. You'll add two fields: one for the fire name and one for the fire acreage.

4. For the new field, change Field Name to Name. Double-click the Data Type cell and choose Text.

   

5. On the ribbon, on the Fields tab, in the Manage Edits group, click Save.

   

   Note:

   If you have unsaved edits from when you digitized the fire features, you won't be able to save changes to the attribute table. If you can't save, close the attribute table without saving, save your feature edits on the Edit tab, and add the new field again.

6. Click the bottom of the list of fields to add another field.
7. Change the name of the new field to Acres and the Data Type to Float.

   

8. On the ribbon, click Save.
9. Close the Fields view to return to the attribute table.

   The new fields have been added to the table. They have Null for their values.

   

   You'll edit the Name fields directly, but to calculate acreage, you'll run a geoprocessing tool.

10. Double-click the Name field for the first feature to edit it. Type Reynolds Creek and press Enter.
11. Change the name of the second feature to Thompson.

    

12. On the ribbon, click the Edit tab. In the Manage Edits group, click Save.
13. In the confirmation window, click Yes to save all edits.
14. In the attribute table, right-click the Acres field heading and choose Calculate Field.

    

    The Calculate Field tool opens. This tool allows you to create an expression to determine field values. The Fires feature class already has an area field, but it's in square meters, not acres. One acre equals 4,046.86 square meters, so you'll use this conversion factor to calculate acreage.

15. Under Expression, in the Fields column, double-click Shape_Area to add it to the expression box. Click the division operator and type 4046.86 after it.

    

16. Click OK.

    The Acres field is calculated.

    

    The Reynolds Creek Fire is approximately 4,400 acres, and the Thompson Fire is approximately 12,000 acres. Your values will vary because you digitized your features differently.

17. Close the Fires attribute table.
18. Save the project.

Share your results

Lastly, you'll share the Fires feature class to ArcGIS Online.

1. In the Contents pane, right-click the Fires layer, point to Sharing, and choose Share As Web Layer.

   The Share As Web Layer pane appears. Before you can share a layer, you must input metadata so it can be searched for and catalogued.

2. In the Share Web Layer pane, enter the following information:
   • For Name, replace the existing text with Glacier National Park Fires. Add your name or initials to the end of the name to make it unique.
   • For Summary, copy and paste the text Perimeter definition of the Reynolds Creek and Thompson fires in Glacier National Park during the summer of August 2015. Perimeters defined by difference in Normalized Burn Ratio.
   • For Tags, type Fire, Reynolds Creek, Thompson, Glacier National Park, Montana and press Enter.
3. For Sharing Level, choose to share with either Everyone or your organization, depending on who you want to see your web layer.
4. Click Analyze.

   

   The layer is analyzed for errors. If metadata is missing or there is something wrong with the data, the error will be catalogued and described so you can fix it.

   The error Unique numeric IDs are not assigned appears. You'll resolve the error.

5. Double-click the error.

   

   The Map Properties window appears.

6. On the General tab, check the box next to Allow assignment of unique numeric IDs for sharing web layers.

   

7. Click OK.
8. In the Share As Web Layer pane, click Analyze.

   The errors have resolved and there are no further errors in the analyzer results.

9. Click Publish.

   The layer is published to ArcGIS Online.

10. At the bottom of the pane, click Manage the web layer.

    

    A new browser window appears.

11. If prompted, sign in to your ArcGIS account (the same one you used to sign in to ArcGIS Pro).

    The item page for your Glacier_National_Park_Fires feature layer appears.

12. Click Open in Map Viewer.

    

    The layer you shared containing the digitized fire boundaries appears in the map.

    

    The layer can now be added to any number of new maps and its symbolization can be customized.

In this tutorial, you used Landsat imagery to determine the extent of two fires. You first looked at the imagery through various spectral band combinations to visually assess the fire location. Then, you calculated the Normalized Burn Ratio to specifically highlight burned areas. Lastly, you digitized both fires and shared them to ArcGIS Online. In a real-world scenario, the Montana Department of Forestry and Resource Management could then use your layer for vegetation succession studies or to plan for future fires in the area.

You can find more tutorials such as this on the Introduction to Imagery & Remote Sensing page.

You can find more tutorials in the tutorial gallery.

Acknowledgements

• Landsat imagery data acquired from the GloVis app hosted by the United States Geological Survey (USGS).
• World Topographic Map sources: Esri, TomTom, Garmin, FAO, NOAA, USGS, OpenStreetMap contributors, and the GIS User Community